"I think he's going to be all right," Frazier said. "We got to give him a few days with his foot and he should be all right."

Williams missed his second straight practice today after seeing a foot specialist in the Twin Cities on Monday. He'll miss the last two preseason games but is expected to play in the regular season opener in San Diego on Sept. 11.

"Everything [the doctors] tell me, if we rest him, he should be fine for the season opener," Frazier said. "So that's what we're crossing our fingers hoping for."

Frazier said orthotics will not help the pain of plantar faciitis. Rest and treatment are the only was to deal with it.

Said Williams: "It's nothing bad. It's just resting up. I just don't want to injure anything or not know what's going on."

As for whether he thinks he'll definitely play on Sept. 11, Williams smiled and said, "Well, I can't tell you that exactly with that other situation going on." Williams still faces a four-game suspension stemming from his positive test for a banned StarCaps diuretic in 2008.

Meanwhile, right guard Scott Kooistra remains hospitalized in Seattle with a serious neck injury. He's in stable condition after suffering a season-ending injury in Saturday night's 20-7 win over the Seahawks.

"He's still out in Seattle and we're not sure what they're going to do, whether it's goinig to be surgery, not surgery," Frazier said. "We're waiting to find out."

Other updates from a 2 hour, 15 minute full-padded practice:

Defensive coordinator Fred Pagac said Jamarca Sanford and Tyrell Johnson remain in a dead heat for the starting strong safety position. Pagac said he thinks Sanford will start against the Cowboys on Saturday. Each player has started one preseason game to this point.

Offensive coordinator Bill Musgrave said the team hasn't decided whether Christian Ponder or Joe Webb will be the No. 2 quarterback on Saturday, but Ponder was with the second team today.

Pagac said the defensive starters will play at least the first half on Saturday.

Percy Harvin looked exceptional in practice today. He made a catch as good as Ben Revere's, leaping high into the air and snagging a deep ball one-handed. He also bowled over rookie safety Ryan Hill on a running play.

Matt Vensel is in his first year at the Star Tribune after covering the Ravens for the Baltimore Sun for six years. He is a Pittsburgh native and a Penn State grad. Follow him at @mattvensel.

Mark Craig has covered the NFL for 23 years, and the Vikings since 2003 for the Star Tribune. He is one of 44 Pro Football Hall of Fame selectors. Follow him at @markcraignfl.

Master Tesfatsion is the Star Tribune’s digital Vikings writer. He is a 2013 graduate of Arizona State and worked for mlb.com before arriving in Minneapolis. Follow him at @masterstrib.